Hello everyone,
We are experiencing issue in our project after upgrading Apache Camel from
version 3.10.0 to 3.11.0. The same route which worked without any problems in
previous versions, does not work now. We managed to simplify the route from our
project and simulate the problem on this simplified route.
Route looks like this:
// HTTP Input
from("servlet:///httpIssue?httpMethodRestrict=GET&servletName=CamelServlet")
.log("Http request received")
.process(new CorrelationIdGenerator())
.to(parallelSplitterEndpoint);
// Parallel Splitter
from(parallelSplitterEndpoint)
.log("Parallel Splitter")
.multicast()
.executorService(executorService)
.parallelProcessing()
.to(new String[]{synchronizerEndpoint});
// Parallel Synchronizer
from(synchronizerEndpoint)
.log("Parallel Synchronizer")
.setHeader("scaler-sync-correlation", correlationExpression)
.aggregate(correlationExpression, new MyRoutesAggregator())
.completionSize(1)
.to(httpOutputEndpoint);
// HTTP Output
from(httpOutputEndpoint)
.log("HTTP Output")
.process(new ProcessHttpOutput());
In ProcessHttpOutput processor we are writing the response into the
OutputStream:
private static class ProcessHttpOutput implements Processor {
@Override
public void process(Exchange exchange) throws Exception {
HttpServletResponse response =
exchange.getMessage().getBody(HttpMessage.class).getResponse();
response.setStatus(200);
try (ServletOutputStream outputStream = response.getOutputStream()) {
outputStream.write(("Response").getBytes(StandardCharsets.UTF_8));
outputStream.flush();
}
}
}
If we run this route on Camel version 3.11.0. We are getting
NullPointerException during flushing / closing the stream. It works without any
problems on 3.10.0.
The problem is only when using multicast and subsequent aggregation in the
route (without aggregation it works fine). After aggregation, it is not
possible to write to the output stream.
Here is the repository with the simplified route (branch camel-minimal-sample):
https://github.com/bugs84/springboot-camel-httpoutput-issue/tree/camel-minimal-sample
Steps to reproduce:
1. Run Application.java
2. Route configuration is located in HttpOutputIssue.java
3. Make GET request to http://localhost:8080/camel/httpIssue
Can you please confirm that this is a bug? Or is it misconfiguration? We will
be grateful for any help with this issue.
Thank you
Michael
